diff options
Diffstat (limited to 'epan/dissectors/packet-bmc.c')
| -rw-r--r-- | epan/dissectors/packet-bmc.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/epan/dissectors/packet-bmc.c b/epan/dissectors/packet-bmc.c new file mode 100644 index 00000000..ea2c1952 --- /dev/null +++ b/epan/dissectors/packet-bmc.c @@ -0,0 +1,343 @@ +/* packet-bmc.c + * Routines for Broadcast/Multicast Control dissection + * Copyright 2011, Neil Piercy <Neil.Piercy@ipaccess.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "config.h" + +#include <epan/packet.h> +#include <wsutil/bitswap.h> +#include <epan/asn1.h> /* needed for packet-gsm_map.h */ + +#include "packet-cell_broadcast.h" +#include "packet-gsm_map.h" + +void proto_register_bmc(void); + +static int dissect_bmc_cbs_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); +static int dissect_bmc_schedule_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); +static int dissect_bmc_cbs41_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree); + +static int proto_bmc = -1; +static int hf_bmc_message_type = -1; +static int hf_bmc_message_id = -1; +static int hf_bmc_serial_number = -1; +/* static int hf_bmc_data_coding_scheme = -1; */ +/* static int hf_bmc_cb_data = -1; */ +static int hf_bmc_offset_to_begin_ctch_bs_index = -1; +static int hf_bmc_length_of_cbs_schedule_period = -1; +static int hf_bmc_new_message_bitmap = -1; +static int hf_bmc_message_description_type = -1; +static int hf_bmc_offset_to_ctch_bs_index_of_first_transmission = -1; +static int hf_bmc_broadcast_address = -1; +static int hf_bmc_cb_data41 = -1; +static int hf_bmc_future_extension_bitmap = -1; +static int hf_bmc_length_of_serial_number_list = -1; +static int hf_bmc_ctch_bs_index = -1; + +#define MESSAGE_TYPE_CBS_MESSAGE 1 +#define MESSAGE_TYPE_SCHEDULE_MESSAGE 2 +#define MESSAGE_TYPE_CBS41_MESSAGE 3 + +static const value_string message_type_vals[] = { + {MESSAGE_TYPE_CBS_MESSAGE, "CBS Message"}, + {MESSAGE_TYPE_SCHEDULE_MESSAGE, "Schedule Message"}, + {MESSAGE_TYPE_CBS41_MESSAGE, "CBS41 Message"}, + {0, NULL} +}; + +static const value_string message_description_type_vals[] = { + {0, "Repetition of new BMC CBS message within schedule period"}, + {1, "New BMC CBS message (a BMC CBS message never previously sent)"}, + {2, "Reading advised"}, + {3, "Reading optional"}, + {4, "Repetition of old BMC CBS message within schedule period"}, + {5, "Old BMC CBS message (repetition of a BMC CBS message sent in a previous schedule period)"}, + {6, "Schedule message"}, + {7, "CBS41 message"}, + {8, "no message"}, + {0, NULL} +}; + +static gint ett_bmc = -1; +static gint ett_bmc_message_description = -1; + +static int +dissect_bmc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) +{ + guint8 message_type; + guint8 *reversing_buffer; + gint offset = 0; + gint len; + proto_item *ti; + proto_tree *bmc_tree; + tvbuff_t *bit_reversed_tvb; + + col_set_str(pinfo->cinfo, COL_PROTOCOL, "BMC"); + col_clear(pinfo->cinfo, COL_INFO); + + ti = proto_tree_add_item(tree, proto_bmc, tvb, 0, -1, ENC_NA); + bmc_tree = proto_item_add_subtree(ti, ett_bmc); + + /* Needs bit-reversing. Create a new buffer, copy the message to it and bit-reverse */ + len = tvb_reported_length(tvb); + reversing_buffer = (guint8 *)tvb_memdup(pinfo->pool, tvb, offset, len); + bitswap_buf_inplace(reversing_buffer, len); + + /* Make this new buffer part of the display and provide a way to dispose of it */ + bit_reversed_tvb = tvb_new_child_real_data(tvb, reversing_buffer, len, len); + add_new_data_source(pinfo, bit_reversed_tvb, "Bit-reversed Data"); + + message_type = tvb_get_guint8(bit_reversed_tvb, offset); + proto_tree_add_item(bmc_tree, hf_bmc_message_type, bit_reversed_tvb, offset, 1, ENC_BIG_ENDIAN); + offset++; + col_add_str(pinfo->cinfo, COL_INFO, val_to_str(message_type, message_type_vals,"Reserved 0x%02x")); + + switch (message_type) { + case MESSAGE_TYPE_CBS_MESSAGE: + offset = dissect_bmc_cbs_message(bit_reversed_tvb, pinfo, bmc_tree); + break; + + case MESSAGE_TYPE_SCHEDULE_MESSAGE: + offset = dissect_bmc_schedule_message(bit_reversed_tvb, pinfo, bmc_tree); + break; + + case MESSAGE_TYPE_CBS41_MESSAGE: + offset = dissect_bmc_cbs41_message(bit_reversed_tvb, pinfo, bmc_tree); + break; + + default: + break; + } + + return offset; +} + +static int +dissect_bmc_cbs_message(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) +{ + tvbuff_t *cell_broadcast_tvb; + gint offset = 1; + + dissect_cbs_message_identifier(tvb, tree, offset); + offset += 2; + + dissect_cbs_serial_number(tvb, tree, offset); + offset += 2; + + dissect_cbs_data_coding_scheme(tvb, pinfo, tree, offset); + offset += 1; + + cell_broadcast_tvb = tvb_new_subset_remaining(tvb, offset); + dissect_umts_cell_broadcast_message(cell_broadcast_tvb, pinfo, tree, NULL); + offset = tvb_reported_length(cell_broadcast_tvb); + + return offset; +} + +static int +dissect_bmc_schedule_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree) +{ + gint offset = 1, i, saved_offset; + guint8 new_message_bitmap_len; + guint8 length_of_cbs_schedule_period; + guint8 message_description_type; + guint8 future_extension_bitmap; + guint8 length_of_serial_number_list; + guint8 entry; + guint8 bit; + proto_tree *message_description_tree; + proto_item *ti; + + proto_tree_add_item(tree, hf_bmc_offset_to_begin_ctch_bs_index, tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + + length_of_cbs_schedule_period = tvb_get_guint8(tvb,offset); + proto_tree_add_item(tree, hf_bmc_length_of_cbs_schedule_period, tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + + new_message_bitmap_len = length_of_cbs_schedule_period>>3; + if (length_of_cbs_schedule_period & 0x7) + new_message_bitmap_len += 1; + + proto_tree_add_item(tree, hf_bmc_new_message_bitmap, tvb, offset, new_message_bitmap_len, ENC_NA); + offset += new_message_bitmap_len; + + message_description_tree = proto_tree_add_subtree(tree, tvb, offset, 0, + ett_bmc_message_description, &ti, "Message Description" ); + saved_offset = offset; + + bit=1; + for (i=0; i<new_message_bitmap_len; i++) { + for(; bit<=length_of_cbs_schedule_period; bit++) { + message_description_type = tvb_get_guint8(tvb,offset); + proto_tree_add_uint_format(message_description_tree, hf_bmc_message_description_type, + tvb, offset, 1, message_description_type, + "Message %d Message Description Type: %s (%d)", + bit, + val_to_str_const(message_description_type, message_description_type_vals,"Unknown"), + message_description_type); + offset += 1; + + if ((message_description_type==1) || (message_description_type==5)) { + proto_tree_add_item(message_description_tree, hf_bmc_message_id, tvb, offset, 2, ENC_BIG_ENDIAN); + offset += 2; + } + else if ((message_description_type==0) || (message_description_type==4)) { + proto_tree_add_item(message_description_tree, hf_bmc_offset_to_ctch_bs_index_of_first_transmission, + tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + } + } + } + proto_item_set_len(ti, offset-saved_offset); + + if (tvb_reported_length_remaining(tvb,offset)) { + future_extension_bitmap = tvb_get_guint8(tvb,offset); + proto_tree_add_item(tree, hf_bmc_future_extension_bitmap, tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + if (future_extension_bitmap & 0x01) { + length_of_serial_number_list = tvb_get_guint8(tvb,offset); + proto_tree_add_item(tree, hf_bmc_length_of_serial_number_list, tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + + for (entry=0; entry<length_of_serial_number_list; entry++) { + proto_tree_add_item(tree, hf_bmc_serial_number, tvb, offset, 2, ENC_BIG_ENDIAN); + offset += 2; + + proto_tree_add_item(tree, hf_bmc_ctch_bs_index, tvb, offset, 1, ENC_BIG_ENDIAN); + offset += 1; + } + } + } + + return offset; +} + +static int +dissect_bmc_cbs41_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree) +{ + gint offset=1; + + proto_tree_add_item(tree, hf_bmc_broadcast_address, tvb, offset, 5, ENC_NA); + offset += 5; + + proto_tree_add_item(tree, hf_bmc_cb_data41, tvb, offset, tvb_reported_length_remaining(tvb,offset), ENC_NA); + offset = tvb_reported_length(tvb); + + return offset; +} + +void +proto_register_bmc(void) +{ + static hf_register_info hf[] = { + { &hf_bmc_message_type, + { "Message Type", "bmc.message_type", + FT_UINT8, BASE_DEC, VALS(message_type_vals), 0, + NULL, HFILL } + }, + { &hf_bmc_message_id, + { "Message ID", "bmc.message_id", + FT_UINT16, BASE_HEX, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_serial_number, + { "Serial Number", "bmc.serial_number", + FT_UINT16, BASE_HEX, NULL, 0, + NULL, HFILL } + }, +#if 0 + { &hf_bmc_data_coding_scheme, + { "Data Coding Scheme", "bmc.data_coding_scheme", + FT_UINT8, BASE_HEX, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_cb_data, + { "CB Data", "bmc.cb_data", + FT_BYTES, BASE_NONE, NULL, 0, + NULL, HFILL } + }, +#endif + { &hf_bmc_offset_to_begin_ctch_bs_index, + { "Offset to Begin CTCH Block Set Index", "bmc.offset_to_begin_ctch_bs_index", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_length_of_cbs_schedule_period, + { "Length of CBS Schedule Period", "bmc.length_of_cbs_schedule_period", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_new_message_bitmap, + { "New Message Bitmap", "bmc.new_message_bitmap", + FT_BYTES, BASE_NONE, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_message_description_type, + { "Message Description Type", "bmc.message_description_type", + FT_UINT8, BASE_DEC, VALS(message_description_type_vals), 0, + NULL, HFILL } + }, + { &hf_bmc_offset_to_ctch_bs_index_of_first_transmission, + { "Offset to CTCH BS index of first transmission", "bmc.offset_to_ctch_bs_index_of_first_transmission", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_broadcast_address, + { "Broadcast Address", "bmc.broadcast_address", + FT_BYTES, BASE_NONE, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_cb_data41, + { "CB Data41", "bmc.cb_data41", + FT_BYTES, BASE_NONE, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_future_extension_bitmap, + { "Future Extension Bitmap", "bmc.future_extension_bitmap", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_length_of_serial_number_list, + { "Length of Serial Number List", "bmc.length_of_serial_number_list", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + }, + { &hf_bmc_ctch_bs_index, + { "CTCH BS Index", "bmc.ctch_bs_index", + FT_UINT8, BASE_DEC, NULL, 0, + NULL, HFILL } + } + }; + + static gint *ett[] = { + &ett_bmc, + &ett_bmc_message_description + }; + + proto_bmc = proto_register_protocol("Broadcast/Multicast Control", "BMC", "bmc"); + register_dissector("bmc", dissect_bmc, proto_bmc); + + proto_register_field_array(proto_bmc, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 4 + * tab-width: 8 + * indent-tabs-mode: nil + * End: + * + * vi: set shiftwidth=4 tabstop=8 expandtab: + * :indentSize=4:tabSize=8:noTabs=true: + */ |